In 1953 the first of the M-48 variants was placed into service in the United States to solve the reliability and performance of the M-47. Serving with distinction in Korea and Vietnam, the M-48A and its later versions were exported to almost two dozen countries, many of which still use the M-48 as their main battle tank. Currently the M-48 system tank is not used in the United States, but remains an important part of the arsenals of other countries
The M-48 was in South Korean service in several models, including the M48A5K, M48A5, M48A3K, and the M48A2C. Between 1976 and 1985 Hyundai retrofited the old-fashioned M48 tank to a new M48A3K and M48A5K improved in mobility/firing capability/protection level, which led to outstanding leaps in Korean defence forces. It is anticipated that additional countries will embark on M-48 modernization programs such as the Korean operation. The ROK version feature side armor skirts and fire control night vision targeting system.
The M48A5K was what the earlier M48 models were called after their firepower had been upgraded and a new suspension had been added. The M48A5K version is further distinguished by the addition of a wind sensor on the rear half of the turret. The M48A5K South Korean variant with a 105mm gun and improved FC system is considered more capable than early M60s.
The M48A5 replaced the 90mm from on M48A3 with a 105mm gun. It also added a search light, a range finder and a ballistic calculator. The M48A5 was created to bring the M48 series up to the standard the M60 series had set.
The M48A3K was created from the M48A1, M48A2 and M48A3, replacing the gasoline engine previously used with a diesel engine, and additional improvements in smoke shell firing and a fire control system from Korea.